1. Field of Invention
The present inventin relates to a door lock structure comprising one or two locking bolts displaceably engaged in a longitudinal cavity provided in a door vertical free edge portion or a folding door edge post or the like door closures and wherein the bolt is automatically held in a locked position when manually extended to a locking position and released by means of a key-operated cam which is accessible from an outer face of the edge portion of the door or door post.
2. Description of Prior Art
A multitude of door lock structures exist utilizing locking bolts. However, with accordion-type folding doors, sometimes referred to as closure screens to close off an open store front, such as in a shopping mall, the only type of lock that exists is of the latch type which is normally located at the center of the edge post. These latch-type locks either engage between edge posts when two folding screens are provided on either side of an opening, or else they will engage in a fixed vertical column provided on a side wall of the opening. A disadvantage of such latches is that they are easily opened by applying wedge pressure between the edge post and vertical column in an area adjacent the latch. Another disadvantage of these latches is that the door structures are usually not very structurally strong, and by applying wedge pressure the locked edge is pried open. A still further disadvantage of these door locks is that the lock is only operated from the outside wall of the screen structure. Because the lock cylinder is on the outside wall of the door structure, one cannot lock the door while inside the area to be closed off by the door, and the door therefore can be closed, but in an unlocked position. This does not provide adequate protection, for example, to a jewellery shop or to the people inside the enclosure.